Preparation method of highly active electrode by one-step modification of ordinary metal nanocomposite surface with two noble metals

Abstract

The invention belongs to the field of electrochemical electrode materials and especially relates to a preparation method of a high-activity electrode with two precious metals one-step modifying commonmetal nanocomposite surface. The preparation method comprises the following steps: firstly preparing a Ni / graphene composite material and coating the surface of a processed glassy carbon electrode with the Ni / graphene composite material, and drying at room temperature to obtain an Ni / graphene electrode; then using the Ni / graphene electrode as a working electrode, using a Pt plate as a counter electrode, using a saturated calomel electrode as a reference electrode, depositing Au and Pt through one-step reduction onto the surface of graphene-loaded Ni nanoparticles in an acid solution of a precursor containing Au and Pt under the condition of constant potential so as to prepare an AuPt / Ni / graphene electrode with two precious metals one-step modifying common metal nanocomposite. The electrode has high catalytic activity to a glycol oxidation reaction in an alkaline medium. The prepared electrode of the invention has remarkable advantages in both aspects of catalytic activity and cost, and has a wide application prospect.

Description

technical field

[0001] The invention belongs to the field of electrochemical electrode materials, in particular to a preparation method of Au-Pt one-step modified Ni / graphene electrode. Background technique

[0002] Alcohol fuel cell is a kind of electrochemical power source for mobile, stationary and portable, which has broad application prospects. Researchers have conducted extensive research on methanol fuel cells and made great progress. However, methanol has disadvantages such as toxicity, low boiling point, and easy permeation of separation membranes. Therefore, research on finding alternative fuels for methanol has been continuously carried out. Ethanol and ethylene glycol are the most potential substitutes. Ethylene glycol has attracted more and more attention because of its low toxicity, high boiling point, high energy density and high reactivity.

[0003] The electrocatalytic oxidation of alcohols is carried out in acidic and basic media. Under acidic medium con...

Examples

Embodiment 1

[0026] (1) Ni / graphene electrode preparation

[0027] Using the Hummers chemical oxidation method, graphite flakes were prepared into graphite oxide, then 2 mg of graphite oxide was placed in 20 mL of double distilled water, and it was subjected to ultrasonic vibration for 40 min to obtain a brown transparent graphene oxide solution, and then 85 μL of 0.1M Ni (NO 3 ) 2 , and continued ultrasonic oscillation for 20 minutes to obtain about 20mL containing Ni(NO 3 ) 2 and graphene oxide solution; add 40mg NaBH to the above liquid under magnetic stirring 4 , continue to stir for 1.5h, then transfer the sample to a test tube and let it settle for 10h. After the layers were separated, the supernatant was removed, and the residual liquid was ultrasonically treated for 5 min. The resulting 1 mL black ink liquid was a Ni / graphene suspension. Successively use 0.3μm and 0.05μm Al 2 o 3 The surface of the glassy carbon electrode with a diameter of 4 mm is polished by polishing powd...

Embodiment 2

[0033] On the basis of Example 1, prepare AuPt (2s) / Ni / graphene electrode.

[0034] (1) Ni / graphene electrode preparation. Same as step (1) in Example 1.

[0035] (2) Au-Pt one-step modified Ni / graphene electrode. Ni / graphene electrode is as working electrode, and Au-Pt deposition time is 2s, and other conditions are identical with step (2) in embodiment 1, prepares AuPt (2s) / Ni / graphene electrode. The amount of Au-Pt deposited according to the amount of charge in the deposition process is about 0.70 μg / cm 2 .

[0036] (3) AuPt (2s) Catalytic activity of / Ni / graphene electrode for ethylene glycol oxidation in alkaline media. Working electrode is AuPt (2s) / Ni / graphene electrode, other conditions are identical with step (3) in embodiment 1, and result is as follows figure 2 shown. AuPt (2s) The peak potential of the ethylene glycol oxidation reaction on the / Ni / graphene electrode is -0.19V, and the peak current density is 21.7mA / cm 2 .

technical field

[0001] The invention belongs to the field of electrochemical electrode materials, in particular to a preparation method of Au-Pt one-step modified Ni / graphene electrode. Background technique

[0002] Alcohol fuel cell is a kind of electrochemical power source for mobile, stationary and portable, which has broad application prospects. Researchers have conducted extensive research on methanol fuel cells and made great progress. However, methanol has disadvantages such as toxicity, low boiling point, and easy permeation of separation membranes. Therefore, research on finding alternative fuels for methanol has been continuously carried out. Ethanol and ethylene glycol are the most potential substitutes. Ethylene glycol has attracted more and more attention because of its low toxicity, high boiling point, high energy density and high reactivity.

[0003] The electrocatalytic oxidation of alcohols is carried out in acidic and basic media. Under acidic medium con...

Examples

Embodiment 1

[0026] (1) Ni / graphene electrode preparation

[0027] Using the Hummers chemical oxidation method, graphite flakes were prepared into graphite oxide, then 2 mg of graphite oxide was placed in 20 mL of double distilled water, and it was subjected to ultrasonic vibration for 40 min to obtain a brown transparent graphene oxide solution, and then 85 μL of 0.1M Ni (NO 3 ) 2 , and continued ultrasonic oscillation for 20 minutes to obtain about 20mL containing Ni(NO 3 ) 2 and graphene oxide solution; add 40mg NaBH to the above liquid under magnetic stirring 4 , continue to stir for 1.5h, then transfer the sample to a test tube and let it settle for 10h. After the layers were separated, the supernatant was removed, and the residual liquid was ultrasonically treated for 5 min. The resulting 1 mL black ink liquid was a Ni / graphene suspension. Successively use 0.3μm and 0.05μm Al 2 o 3 The surface of the glassy carbon electrode with a diameter of 4 mm is polished by polishing powd...

Embodiment 2

[0033] On the basis of Example 1, prepare AuPt (2s) / Ni / graphene electrode.

[0034] (1) Ni / graphene electrode preparation. Same as step (1) in Example 1.

[0035] (2) Au-Pt one-step modified Ni / graphene electrode. Ni / graphene electrode is as working electrode, and Au-Pt deposition time is 2s, and other conditions are identical with step (2) in embodiment 1, prepares AuPt (2s) / Ni / graphene electrode. The amount of Au-Pt deposited according to the amount of charge in the deposition process is about 0.70 μg / cm 2 .

[0036] (3) AuPt (2s) Catalytic activity of / Ni / graphene electrode for ethylene glycol oxidation in alkaline media. Working electrode is AuPt (2s) / Ni / graphene electrode, other conditions are identical with step (3) in embodiment 1, and result is as follows figure 2 shown. AuPt (2s) The peak potential of the ethylene glycol oxidation reaction on the / Ni / graphene electrode is -0.19V, and the peak current density is 21.7mA / cm 2 .

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